Pounds and ounces to kg
Enter pounds and ounces in separate boxes to get kilograms. 7 lb 8 oz is 120 ounces, and 120 × 28.349523125 g = 3 401.9 g, or 3.4019 kg.
Pounds and ounces to kilograms converter
Rounded: 7 lb 8 oz · 3.4019 kg · 7.5 lb
Answers show 5 significant figures; the rounded line uses the step you pick here.
How it’s calculated
1 lb = 16 oz · 1 oz = 28.349523125 g exactly · 1 lb = 0.45359237 kg
kg = (pounds × 16 + ounces) × 0.028349523125
Step by step
- Turn the pounds into ounces: 7 × 16 = 112 oz.
- Add the ounces: 112 + 8 = 120 oz.
- Multiply by 28.349523125 (g per ounce, exact): 120 × 28.349523125 = 3,401.9 g = 3.4019 kg.
Baby weight conversion table
| Pounds and ounces | Kilograms | Grams |
|---|---|---|
| 4 lb 0 oz | 1.8144 kg | 1,814.4 g |
| 4 lb 4 oz | 1.9278 kg | 1,927.8 g |
| 4 lb 8 oz | 2.0412 kg | 2,041.2 g |
| 4 lb 12 oz | 2.1546 kg | 2,154.6 g |
| 5 lb 0 oz | 2.268 kg | 2,268 g |
| 5 lb 4 oz | 2.3814 kg | 2,381.4 g |
| 5 lb 8 oz | 2.4948 kg | 2,494.8 g |
| 5 lb 12 oz | 2.6082 kg | 2,608.2 g |
| 6 lb 0 oz | 2.7216 kg | 2,721.6 g |
| 6 lb 4 oz | 2.835 kg | 2,835 g |
| 6 lb 8 oz | 2.9484 kg | 2,948.4 g |
| 6 lb 12 oz | 3.0617 kg | 3,061.7 g |
| 7 lb 0 oz | 3.1751 kg | 3,175.1 g |
| 7 lb 4 oz | 3.2885 kg | 3,288.5 g |
| 7 lb 8 oz | 3.4019 kg | 3,401.9 g |
| 7 lb 12 oz | 3.5153 kg | 3,515.3 g |
| 8 lb 0 oz | 3.6287 kg | 3,628.7 g |
| 8 lb 4 oz | 3.7421 kg | 3,742.1 g |
| 8 lb 8 oz | 3.8555 kg | 3,855.5 g |
| 8 lb 12 oz | 3.9689 kg | 3,968.9 g |
| 9 lb 0 oz | 4.0823 kg | 4,082.3 g |
FAQ
Useful for baby weights, parcels and fishing catches: anything weighed in pounds and ounces on one scale and kilograms on another.
How do I convert a baby’s weight from kg to pounds and ounces?
Multiply the kilograms by 2.20462 to get pounds. The whole number is the pounds; multiply the decimal part by 16 to get the ounces. 3.5 kg = 7.7162 lb = 7 lb 11.5 oz.
How many ounces are in a pound?
There are exactly 16 avoirdupois ounces in a pound in both the US and the UK. A pound is exactly 0.45359237 kg and an ounce is 28.349523125 g.
What is an average birth weight?
Many full-term babies weigh between about 2.5 kg and 4 kg (roughly 5 lb 8 oz to 8 lb 13 oz). Your midwife, doctor or health visitor is the right person to interpret your own baby’s weight and growth chart.
Why do hospitals use kilograms?
Hospitals in most countries, and many in the US, weigh babies in grams or kilograms because medicine doses are calculated per kilogram. Families often still share the weight in pounds and ounces.
Is Unitglide accurate enough for medical use?
Unitglide uses the exact legal definition of the pound and ounce, so the arithmetic is exact. For feeding or medication decisions always follow the figures your clinician gives you.
Sources
- NIST Handbook 44, Appendix C (General Tables of Units of Measurement): 1 in = 2.54 cm exactly; 1 lb = 0.45359237 kg exactly; 1 lb = 16 oz.
Checked by Unitglide on 2026-10-27.